For example, an STN-type liquid crystal apparatus has been disclosed in Japanese Unexamined Patent Publication No. 7-191296 (published date: Jul. 28, 1995, “A liquid crystal apparatus”). This liquid apparatus includes a display cell holding a nematic liquid crystal layer between a first substrate having a first transparent electrode and a second substrate having a second transparent electrode, and an optical anisotropic member for correcting a phase difference structured using a polymer film or a compensating liquid crystal cell between a second polarization board and the second substrate which are provided between a first polarization board and the second polarization board.
According to this document, the nematic liquid crystal layer of the display cell (corresponding to the liquid crystal devices) is twisted and oriented by 120° or more, and a twist angle and a retardation Δnd of the optical anisotropic body are set to predetermined conditions in accordance with the twist angle of the nematic liquid crystal layer and the retardation Δnd which is obtained by a product of a double refractive index Δn and a gap “d” between substrates, so that undesirable color on the display, occurring during a turned on/off state of the liquid crystal devices, can be resolved.
In this document, however, since the twist angle and the retardation Δnd of the optical anisotropic member (corresponding to the twisted phase difference board) are set in accordance with the twist angle and the retardation Δnd of the nematic liquid crystal layer, the following items (1) to (6) have not yet defined concretely. That is, (1) a relationship of an angle between a direction of the twist angle of the twisted phase difference board and the direction of the twist angle of the liquid crystal device; (2) the relationship of the angle between an oriented direction of the liquid crystal molecule of an alignment film of the second substrate and a molecule-oriented direction of a lower polymer of the twisted phase difference board; (3) the relationship of the angle between an absorption axis of the first polarization board and the oriented direction of the liquid crystal molecule of the alignment film of the first substrate; (4) the relationship of an angle between an absorption axis of the second polarization board and the oriented direction of the molecule of an upper polymer of the twisted phase difference board; (5) the relationship between the double refractive index of the nematic liquid crystal layer and the double refractive index of the twisted phase difference board; and (6) preferential view angles at the liquid crystal layer of the liquid crystal device. Accordingly, in this document, an optimum display quality has not yet been realized for resolving undesirable color on the display occurring during the turned on/off state of the liquid crystal device.